A GOP redistricting plan also will likely shore up freshmen Republican Reps. Dan Benishek in the Upper Peninsula and Tim Walberg in southern Michigan.
-- Massachusetts grew by a slow 3.1 percent in the last decade. The slowest-growing parts of the state have been in the west and along the South Shore. Berkshire and Franklin counties in the west lost population, and Hampshire and Hampden counties didn't grow by much. The South Shore county of Barnstable also lost population.
The Boston area grew a little faster: The city itself grew by almost 5 percent, while surrounding Suffolk County grew by about the same rate. Nearby Norfolk and Middlesex counties grew by about the same rate as the state as a whole.
Massachusetts' slow growth will cost it a congressional seat in reapportionment. Democrats control the state, but they will have to eat one of their own as the state hasn't elected a Republican congressman since 1994. Party leaders have been trying to goad one of the congressmen into challenging Sen. Scott Brown (R), but have yet to succeed.
If no incumbents run or retire, the most obvious target would be freshman Democratic Rep. Bill Keating, who has the least clout in the delegation and represents Barnstable County, which shrank. But Keating's district is tough to carve up because much of it is surrounded by ocean. Scenarios abound, and if no Democrat retires or runs for the Senate, Democrats could have an ugly intra-party battle.
-- New Hampshire grew faster than its southern neighbor, partially because some from Massachusetts have moved north. The Granite State grew by 6.5 percent, with the fastest growth in Dover and Bedford. Nashua, the closest large town to Massachusetts, shrank slightly, but the south of the state grew faster than the north.
New Hampshire has a Republican legislature with a veto-proof majority over Democratic Gov. John Lynch, and it picked up both House seats last year after losing both in 2006. It is unlikely the GOP can shore up either of its freshmen House members without endangering the other, so the two districts, which have remained largely unchanged since the 1880s, will likely remain about the same.